x86/pci: Reducde #ifdeffery in PCI init code

Adding a function call before the first #ifdef in arch_pci_init() triggers
a 'mixed declarations and code' warning if PCI_DIRECT is enabled.

Use stub functions and move the #ifdeffery to the header file where it is
not in the way.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20200826112332.767707340@linutronix.de

arch/x86/include/asm/pci_x86.h

@@ -114,9 +114,20 @@ extern const struct pci_raw_ops pci_direct_conf1;
 extern bool port_cf9_safe;
 
 /* arch_initcall level */
+#ifdef CONFIG_PCI_DIRECT
 extern int pci_direct_probe(void);
 extern void pci_direct_init(int type);
+#else
+static inline int pci_direct_probe(void) { return -1; }
+static inline  void pci_direct_init(int type) { }
+#endif
+
+#ifdef CONFIG_PCI_BIOS
 extern void pci_pcbios_init(void);
+#else
+static inline void pci_pcbios_init(void) { }
+#endif
+
 extern void __init dmi_check_pciprobe(void);
 extern void __init dmi_check_skip_isa_align(void);
 

arch/x86/pci/init.c

@@ -8,11 +8,9 @@
    in the right sequence from here. */
 static __init int pci_arch_init(void)
 {
-#ifdef CONFIG_PCI_DIRECT
-	int type = 0;
+	int type;
 
 	type = pci_direct_probe();
-#endif
 
 	if (!(pci_probe & PCI_PROBE_NOEARLY))
 		pci_mmcfg_early_init();
@@ -20,18 +18,16 @@ static __init int pci_arch_init(void)
 	if (x86_init.pci.arch_init && !x86_init.pci.arch_init())
 		return 0;
 
-#ifdef CONFIG_PCI_BIOS
 	pci_pcbios_init();
-#endif
+
 	/*
 	 * don't check for raw_pci_ops here because we want pcbios as last
 	 * fallback, yet it's needed to run first to set pcibios_last_bus
 	 * in case legacy PCI probing is used. otherwise detecting peer busses
 	 * fails.
 	 */
-#ifdef CONFIG_PCI_DIRECT
 	pci_direct_init(type);
-#endif
+
 	if (!raw_pci_ops && !raw_pci_ext_ops)
 		printk(KERN_ERR
 		"PCI: Fatal: No config space access function found\n");